High apoB/apoA-I ratio is associated with increased progression rate of carotid artery intima-media thickness in clinically healthy 58-year-old men: Experiences from very long-term follow-up in the AIR study

Objectives: The aim of the present study was to investigate the relationship between atherosclerotic progression rate as measured by carotid artery IMT during very long-term follow-up in clinically healthy men and a number of baseline risk factors of potential importance for atherosclerosis progression including apoA-I, apoB, apoB/apoA-I ratio, other lipid variables including LDL particle size, body composition variables, blood pressure, smoking, fasting blood glucose and insulin, and also hsCRP. Background: Low-density lipoprotein (LDL) is associated with increased carotid IMT progression rate during long-term follow-up, whereas the relationship between newer biomarkers such as apoB/apoA-I ratio and carotid artery IMT progression rate has been less investigated. Methods: 58-year-old men identified by screening in the community (n = 391) with varying degrees of obesity and insulin sensitivity were examined with high-resolution B-mode ultrasound at baseline and after 3, and 8.9 years of follow-up (n = 305 investigated after 8.9 years). The carotid arteries were examined bilaterally, and the mean intima-thickness was calculated for 10 mm sections of the composite of common carotid arteries and bulbs (IMT(composite)). Serum levels of apoB and apoA-I were measured using a turbidimetric method. Uni- and multi-variable analyses were performed to study the relationship between carotid IMT(composite) progression rate and risk factors. Results: In a multi-variable analysis including all baseline variables only the apoB/apoA-I ratio (p = 0.003; beta=0.181, standard error=0.003) and serum insulin (p=0.026; beta=-0.133, standard error=0.000) was significantly related to IMT(composite) progression rate. Conclusion: The results indicate that apoB/apoA-I ratio is an important risk factor for predicting atherosclerotic progression rate during very long-term follow-up in clinically healthy middle-aged men. (C) 2008 Elsevier Ireland Ltd. All rights reserved.